Broadcast systems with transmitters that transmit unidirectional broadcast signals via an air interlace, for example a radio or television transmitter, do not dispose of a return channel. For the purpose of obtaining data about program quality and/or reception quality of the broadcast systems, separate communication channels must be used. For the determination of the reception quality, or rather the signal quality of the broadcast signals, special mobile measuring stations are usually used by the operator of a broadcast station that serve to measure the received radio signals at different locations in the transmission area of the broadcast station and will register the measured values for later evaluation on a data carrier record. For the determination of commercial program quality, or rather of the programs selected by users and of the relative audience numbers, usually the opinions of consumers (television viewers or radio listeners) are recorded in writing, by telephone or via special data acquisition devices. The data acquisition devices store input data on a data carrier or transmit said data via the public switched telephone network to an analyzing center.
In the published patent application WO01/43364 an interactive media system is described, in which radio listeners or television viewers (users) can transmit user instructions via mobile terminals to a central office. The mobile terminals in accordance with WO01/43364 include a broadcast receiver, a GPS-receiver (Global Positioning System) and a wireless transmitter. The user instructions will be transmitted to the central office in accordance with WO01/43364 together with the current geographical position, the momentary adjusted frequency of the radio-receiver, the current time data and user identification, after pressing a determined control button of the mobile terminal by the user. In accordance with WO01/43364 the respective broadcasting program that is listened to or seen by the user will be identified thanks to the received information. In accordance with WO01/43364, the central office obtains information from a database concerning the identified broadcasting program and files this information on the Internet for later access by the user. Although the mobile terminal in the system in accordance with the WO01/43364 disposes of a return channel thanks to the wireless transmitter, the system is not suitable for the statistical data record relating to program quality and/or reception quality of the broadcast systems, since the user instructions are only transmitted to the central office when sent by the user and since no statements can be made about the reception quality, or rather about the signal quality of the broadcast signals.